Enhancing honey production with clover: Innovative methods to use white and alsike clover in Vermont hay fields

Enhancing honey production with clover: Innovative methods to use white and alsike clover in Vermont hay fields

Summary

A decline in honeybee populations in Vermont over the past few decades has been attributed to many factors including mites, disease and a loss of nectar and pollen resources. An important stressor on honeybees in Vermont is the lack of food available to them throughout the summer.     The goal of this project is to increase the acreage of flowering clovers that provide sustained nectar flows during this critical summer period. In 2013, two farms collaborated in establishing field trials to test the feasibility of including white and/or alsike clover in their hay fields. The first trial was planted on May 10 in Weybridge, VT over seeding Dutch white clover into a predominately grass hay field using different seeding rates and methods. In 2015, we found no difference in clover flower head populations amongst treatments..  Another on-farm strip trial was planted in late May 2013 in Bridport, VT comparing pure alfalfa to alfalfa mixed with one of two different white clover varieties or with alsike clover at two seeding rates. A similar trial was planted in small plots at the University of Vermont in August 2013.   Data was collected at both sites in 2014 but only at the UVM site in 2015 (the Bridport site was terminated due to severe winter injury). These trials showed that ‘Pinnacle’ white clover far exceeded ‘Crusade’ white clover and alsike clover in flower abundance and seasonal distribution demonstrating the need for proper cultivar selection. At a 2 to 3 lb. seeding rate when mixed with alfalfa, we found no differences in yield and quality was actually improved.  In 2015, we did find that floral abundance was only about a third of the amount in the previous year most likely due to the very wet followed by very dry conditions.

Objectives/Performance Targets

The first objective was to test the feasibility of improving nectar flow for honeybees by introducing Dutch white clover into grass hay cropping systems and assess its impact on flower production and foraging honeybees. On April 10, 2013, two field trials were implemented. The first was a strip trial at the Duclos-Thompson Farm, a diversified livestock farm, in Weybridge, VT.  This trial was set up in a field that has been in hay for well over five years that is adjacent to a bee yard managed by Champlain Apiaries. The soil type is Vergennes clay, moderately well-drained. The dominate forage species is a mixture of common forage grasses (orchardgrass, bluegrass, timothy), red and white clover and some weeds particularly smooth bedstraw. Treatments were the same as outlined in the proposal including a no-treatment control plus four different seeding scenarios using Dutch white clover: two seeding rates, 2 vs. 4 lbs./a using two methods of seeding, no-till planted with a Haybuster 107C drill. Strips were 50 feet wide and 150 feet long. Due to the size of the strips and field, there were only two replications of each treatment arranged in a randomized block design.

In 2015, flower head data was collected after the first harvest to see if there was any residual effects of the 2013 seeding treatments. Due to the extremely wet month of June, the first cut was not made until the first of July. Then it turned dry and a second harvest was not made until mid-August. Overall, there were no significant differences amongst the treatments. There was no way to distinguish between any Dutch white flower heads from any other cultivar or ecotype that may have already been in the soil seedbank at this site. Clover populations were lower in 2015 than 2013 at this site. This may reflect the year to year variation observed in clover abundance in pastures and hay fields due to rainfall and temperature patterns.    

Our second objective was to test the feasibility of improving nectar flow by growing mixtures of various early maturing legumes with alfalfa managed for hay and assess its impact on flower production, honeybee activity, forage yield and forage quality. Our hypothesis is that early maturing legumes such as medium white clover and/or alsike clover will bloom before the alfalfa is ready to cut. To test this hypothesis, we implemented two trials in 2013. The first one was a strip trial planted at the Huestis farm in Bridport, VT. The site is a Vergennes moderately well, drained clay. Mr. Art Huestis has managed this site for over 40 years successfully growing alfalfa for his dairy herd. The study included seven treatments replicated four times two seeding rates of three clovers. Each plot is 30 by 180 feet. Mr. Huestis planted the whole area on May 3 with a single seeding rate of alfalfa at 10 lb/a. Clover treatments were then broadcast planted within each respective plot using a hand spinner spreader. The clovers included ‘Pinnacle’ and ‘Crusade” white clover and ‘common’ alsike clover seeded at two rates, 2 lbs vs 4 lbs. There is also a non-clover control consisting of alfalfa only. Data collected in 2014 was summarized and reported on the project website. Unfortunately, due to severe winter injury, the site was terminated in 2015.

As part of Objective 2, a second small plot study was seeded August 22, 2013 at the UVM Horticultural Research Farm with similar treatments as those at the Huestis farm. Besides the same treatments as at Heustis farm, it also included a mixture of alfalfa with all three clovers combined seeded at two different seeding rates.   In 2015, we continued to collected clover head populations from each plot every one to two weeks starting in June after the first harvest was made. We also collected yields and made bee activity observations. Results will be posted on the project website. 

Preliminary data collected in 2014 and 2015 from both trials showed the following results:

• White clover was much more prolific at producing flowers compared to alsike clover. After the each harvest, white clover would produce bloom within the first week to 10 days after regrowth and would continue to bloom until the next harvest.   Alsike clover flowers heads took longer to develop than white clover and would not have a significant number of flower heads until at least two to three weeks into regrowth.
• There were also differences in white clover cultivars probably due to their sensitivities to day length. At the Huestis and UVM site, ‘Pinnacle’ white clover generally produced far more flower heads than ‘Crusade’ white clover or alsike clover. At the UVM site, ‘Crusade’ had more flower heads in June but tapered off in July and August while ‘Pinnacle’ had significantly more in July and August. Extrapolating from 20 inch square quadrats, the alfalfa/ ‘Pinnacle’ white clover mixture seeded at a 15 pound alfalfa and 3 pound white clover rate per acre, we measured a flower head population that ranged from 200,000 to 288,000 per acre. However, in 2015, we only had a peak of about 100,000 flower heads per acre and, generally, floral counts were only about a third of that in 2014. This may have been due to a combination of winter injury of the clovers (especially alsike clover), an extremely wet June which may have inhibited flower production, and followed by a very dry period in July and August favoring the deep rooted alfalfa over the shallow rooted clovers.

• There were no significant differences in yield between many of the clover mixtures with that of pure alfalfa, especially when the clover was seeded only at 2 to 3 lbs. per acre. At a 5 lb. rate, the alfalfa appeared to be stressed and had a larger number of weeds. The most stressful treatment was when a three way mixture of clovers were seeded with the alfalfa at the highest seeding rate.

• Forage quality was found to be similar or improved when clovers were mixed with the alfalfa.

• Honeybees and bumble bees were observed working both the white clovers and alsike clover.   The time of day that bees foraged varied from mid-morning to late afternoon.

For Objective 3, a website was developed and posted to provide updates on the research and demonstrations. The URL is http://pss.uvm.edu/beeclover/. We also presented overeiws of the project at a major Pollinator Summit in November and a Certified Crop Advisors meeting in Dec (see Milestones).

Accomplishments/Milestones

April 2015

• Updated the project website (http://pss.uvm.edu/beeclover/) and added data from the 2014 year.
• The project was highlighted in the Vermont Farm Bureau magazine “Vermont Fences” in their Spring 2014 edition.

May 2015

• Presented an “Across the Fence” television program (Bosworth and Mraz) about the project and discussed pollinator protection (estimated 20,000 viewers).
• Visual observations were made for all studies. The Huetis site was found to be severely winter injured; thus, the study was terminated. The UVM site was in relatively good shape.
• Plots at the UVM site were hand weeded for curly dock and white campion.

June to Sept 2015

• Collected data on clover flower counts at the UVM site approximately once a week from June through September. Collected measurements to estimate yield.
• Collected data on clover flower counts at the Duclos site in July and August. Champlain Valley Apiaries maintained bee colonies to assure active, healthy hives.

Nov/Dec 2015

• Data was analyzed and samples processed for quality analysis
• Charles Mraz and Sid Bosworth presented an overview of the project at the New Hampshire pollinator summit on Nov 2. There were 258 attendees (40 beekeepers, 22 farmers, 43 landscape professionals, 25 educators, 70 government employees and 58 others).  We also had a poster about the project at the Summit and at least 50 handouts of the project were taken at the poster table by participants.
• Sid Bosworth presented an overview of the project to the Northeast Certified Crop Advisor Training in Syracuse, NY Dec. 1. The session was attended by approximately 75 crop advisors.

Jan 2016

• Will present results of the project at the Vermont Grazing and Livestock Conference Jan. 16.
• Will present results at the Vermont Beekeepers Association Meeting Jan. 26.

Impacts and Contributions/Outcomes

As a result of this project, we have raised awareness of the issue of bee decline in Vermont and New England. We have partnered with a New England Pollinator Working Group (sponsored by USDA IPM) and the Vermont Beekeepers Association.

The results of this project has provided some promising findings in regards to using forage legumes as a forage resource for honeybees and bumble bees. As a result of our findings, we have developed a collaboration with an insect/plant ecologist at the University of Vermont to further investigate the feasibility of developing a “bee friendly” hay mixture.

Collaborators: